In my U.S. Pat. No. 4,185,191, issued Jan. 22, 1980, I disclose an invention for use in auto focus cameras to determine the range to a remote object by the use of pairs of detectors mounted in a row behind a corresponding row of small lenslets which receive light from the remote object through the taking lens of the camera. Each of the detector pairs receives an image of the exit pupil of the taking lens and if the object is in proper focus, the amount of radiation received by each detector in the pair will be approximately the same. If the object is not in focus, then the amount of radiation received by the detectors will not be the same and by analyzing the outputs of the individual detectors in each pair, a pair of curves may be generated, the relative displacement of which is indicative of the range to the object.
Also in the prior art are optical systems which utilize a matrix of optical detectors positioned so as to receive an image of a remote object and usually, by use of a properly programmed computer, certain characteristics of the object may be determined. Such systems may be found not only in character recognition systems, but in robotics where arms are controlled to, for example, pick up elements passing by on a conveyor belt.
One difficulty found with robotic systems is that while the computer may be programmed to recognize an object in a two dimensional view thereof, the image processing equipment is not able to simultaneously determine the distance to the object being sensed and accordingly, unless the objects are always positioned a known distance from the robot arm, the robot may not be able to locate the object it wishes to pick up.